1. Field of the Invention
The present invention relates in general to the field of information handling systems and more specifically, to predicting the quality of streaming media over wireless networks.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems configured as portable units have grown in popularity among users over the past several years. These systems generally integrate in a single housing a display, internal power source and processing components, such as the CPU and hard disk drive, so that a user can carry the portable system from place to place while the system is operating. As processing components have decreased in size and increased in performance, portable information handling systems are often able to pack processing capabilities into a relatively small housing that are comparable to the capabilities available from desktop systems.
It is becoming common for portable systems to comprise communications hardware and software that allows connectivity to wireless data networks, such as those based on variants of the 802.11 protocol, sometimes referred to as “Wi-Fi.” These wireless data networks are gaining ubiquity in public venues such as coffee shops, secured Wireless Local Area Networks (WLANs) as subsets of corporate networks, and private homes for wirelessly connecting desktop and media PCs, portable devices such as laptops and Personal Digital Assistants (PDAs), Digital Media Appliances (DMAs) such as video projectors and other devices to each other and to the Internet.
Advances in wireless network performance have enabled the streaming of high quality audio/video content, typically through the use of packet switched or asymmetric transmission methods understood by those of skill in the art. The digitized content stream, which is generally compressed, can be received and rendered by a media player application on a computer but is typically not downloaded and stored, hence the term “streaming.” An advantage of streaming media is it allows users to immediately view or listen to digitized content as it is being transmitted instead of waiting for an entire file to download. To offset the possibility of network transmission delays, a few seconds of data is typically sent ahead, buffered to temporary storage, and then deleted once viewing is complete. Streaming media servers can also provide audio/video content in a variety of streaming formats, such as RealMedia, QuickTime and Windows Media, allowing media player clients implementing different formats to receive and play the same content.
Streaming media can be transmitted and received in a variety of venues, including public (e.g., a coffee shop providing wireless access to the Internet), corporate (e.g., a secured wireless LAN implemented as part of a corporate network), or private (e.g., servers and portable devices wirelessly linked to each other and/or the Internet). For example, a consumer could view a live news broadcast on a wirelessly-enabled laptop computer or personal digital assistant (PDA) while having breakfast in a coffee shop. As another example, a media center PC in a home receives a live, high definition television (HDTV) feed through a wireline broadband connection, and then encodes the content for relay over a wireless network (e.g., 802.11) to a remote or portable device (e.g., laptop computer, remote TV, projector) which then decodes the content for viewing. It will be apparent to those of skill in the art that many such scenarios are possible and the examples given are not meant to be all-inclusive.
However, media streaming poses stringent requirements for network bandwidth, latency and packet loss, all of which can be adversely affected by a variety of factors in a wireless environment and can contribute to an unsatisfactory user experience. Currently, wireless network performance is measured in terms of throughput and range, with the assumption that if a throughput ‘x’ at a certain range is achieved, then video content that is encoded at a bit rate lower than ‘x’ can be streamed and viewed at that range. In practice, this assumption may prove inaccurate as throughput measurements are generally an average of the actual transfer rate over a predetermined time interval, yet the effective throughput rate can drop to levels below such an average during the same time interval. Since streaming media packets containing compressed content are not retransmitted, these drops in effective data transfer rate can adversely affect the quality of the content delivered to the user and even minor losses can result in video artifacts such as jitter, blockiness, dropped frames, and loss of audio synchronization.
Current tools and mechanisms to measure network performance, such as Chariot, produced by NetIQ, or Netperf, a collaborative effort of the FreeBSD network performance project, use various scripts to emulate streaming media applications. While such tools can be useful for determining anticipated network performance when passing typical streams of digitized media, they fail to provide insight into the quality of the delivered audio/video media stream as perceived by the user. Likewise, currently available video performance evaluation methods are not well suited for use in compressed video comparisons as they only compare uncompressed videos at the source and the client, nor do they address wireless network performance factors. Furthermore, current compressed video performance measurement tools, such as produced by industry consortiums such as the Video Quality Experts Group (VQEG) and commercial vendors such as Genista are similarly not suitable because the methods they use are specific to certain coding schemes and cannot be generalized. Current cellular networks have optimizations for voice communications and next generation cellular networks are beginning to target network optimizations for low bitrate video applications, but similar optimizations for wireless data networks (e.g., 802.11, etc.) are not available.
However, there are mechanisms in place to gather standardized statistics for network performance, such as 802.11k, which can provide client application feedback to WLAN access points and switches. Some of the network measurements that 802.11k defines include radio frequency (RF) channel knowledge and a series of measurement requests and reports that detail Layer 1 and Layer 2 client statistics. While access points or WLAN switches generally issue requests to the client to report data, clients can also issue requests for network performance data to facilitate client roaming decisions. While useful for measuring wireless network performance, these statistics and reports are not suitable for measuring the performance of streaming media applications or predicting the quality of the user experience.
Currently, there is no known system or method for a user to know in advance whether their system can support streaming media in a predetermined wireless environment, and if it can be supported, at what level of quality. In addition, streaming media client applications have no way of performing wireless network performance measurements in real-time to determine and indicate to a user the degree to which streaming media applications can be supported. Furthermore, wireless site surveyors are unable to gauge during planning and implementation whether streaming media applications can be adequately supported to meet user expectations. In view of the foregoing, a system and method is needed for testing the anticipated performance of streaming media applications within a predetermined wireless network environment.